carb swap

[flandanery]

I think my carb on my FHMT is junk. I just tore the carb apart and cleaned it, what a mess in side. Got it running again and it revs high then back to normal. does this when idling, high then low, high then low. I have a Walboro carb off a 18cc engine and the bolt pattern is the same, just smaller bore throught the carb. Think this might work or not? I can't keep the FHMT running, it is dying on the low end. My arm and ribs are sore from pulling the thing over so much. Is the Walbro WT603 the carb I want? I just read of some other carbs Walbro type, lower numbers than 603

 

[LP40_FG]

I think my carb on my FHMT is junk. I just tore the carb apart and cleaned it, what a mess in side. Got it running again and it revs high then back to normal. does this when idling, high then low, high then low. I have a Walboro carb off a 18cc engine and the bolt pattern is the same, just smaller bore throught the carb. Think this might work or not? I can't keep the FHMT running, it is dying on the low end. My arm and ribs are sore from pulling the thing over so much.

This could be your throttle settings are to low, doesn't necessarily have to be the carb could be the settings... Its worth a try to take a look mate?

Let us know what happens.

.A

 

[csp1971]

flan -

Check out this thread: https://www.largescaleforums.com/showthread.php?t=2761, specifically, posts 3 & 4.

More good stuff:

http://www.hpibajaforum.com/forum/showpost.php?p=815096&postcount=1

It's possible you could have a blown head gasket or an air leak (check all engine bolts, carb bolts, change fuel lines). Spray wd40 around the carb and engine. If idle goes up, you have a leak.

How old is the engine and carb? Which engine is it? My FHMT came with a three bolt head. Nothing like the 2 bolt or 4 bolt CY's or Zens. The 668 or 603 would work just fine for it.

 

[flandanery]

I definitely have an air leak. I was spraying carb&choke cleaner around the carb and it dies right out, I was figuring on the idle going up but the opposite happened. The engine is a three bolt, and I did find all three bolts loose, about one turn loose on all three.
Let me just start by saying a month ago I found a water hole unexpectedly. The engine died as it should have when getting flogged with water. For two weeks after that incident the engine ran just fine, then it started running bad. I had made new gaskets for the intake starting at the air filter right back to the engine. no luck. I then thought I should pull the carb apart, big mistake with no spare gaskets. Needless to say I got the carb back together but with a thinker gasket between the priming bulb and the diaphragm. The engine didn't run any better or worse. That is when I gave up for the day and found the loose head bolts.
What is the head gasket made from, could I use some regular paper gasket material?
Thanks for the input people.

 

[pablo]

I definitely have an air leak. I was spraying carb&choke cleaner around the carb and it dies right out, I was figuring on the idle going up but the opposite happened. The engine is a three bolt, and I did find all three bolts loose, about one turn loose on all three.
Let me just start by saying a month ago I found a water hole unexpectedly. The engine died as it should have when getting flogged with water. For two weeks after that incident the engine ran just fine, then it started running bad. I had made new gaskets for the intake starting at the air filter right back to the engine. no luck. I then thought I should pull the carb apart, big mistake with no spare gaskets. Needless to say I got the carb back together but with a thinker gasket between the priming bulb and the diaphragm. The engine didn't run any better or worse. That is when I gave up for the day and found the loose head bolts.
What is the head gasket made from, could I use some regular paper gasket material?
Thanks for the input people.

try some rtv gasket sealer with the old gasket, that,ll work,

 

[Bigger the Better]

When you remove the carb check inside the hole and see what your head and piston look like. If your carb was full of crap your motor sucked in crap. You may have a motor issue if crap was sucked into it.

 

[flandanery]

It wound up being an air leak. I got 2 new gaskets and used some gasket compound, the thing fired right up and ran better. After adjusting the needle settings it seems to run better than ever. I should still get a second carb though.